When nature calls, a few intrepid Calgarians are choosing to go green.

Only they’re not flushing their business down a low-flow toilet. They’re composting, turning waste into fertile loam for the garden.

Compostable toilets have been around for decades, but only in the last decade have they begun to catch on—albeit very slowly, says Nancy Herrington, owner of www.letsgogreen.com/, which sells compostable toilets in the city.

“I’ve been selling these since 2004,” says Herrington. “My business has certainly grown since then as people are becoming more and more concerned about water pollution.”

Many customers are cabin owners. Gone are the days of digging a hole and building an outhouse.

“And a full-blown septic system on a recreational property can be cost-prohibitive for many people looking for a simple solution.”

That’s one big reason compostable toilets are becoming a go-to option, she says.

“The upside of using a compostable toilet is you don’t need a sewer connection or a water supply.”

Not to mention they don’t pose a contamination risk to nearby lakes and rivers. Still, a handful of environmentally-conscious Calgarians are buying compostable toilets for their homes in the city.

“They very strongly believe that they don’t want to be polluting the river,” Herrington says.

Although the municipal sewer system cleans wastewater before returning it to nature, there’s something a little perverse about using fresh drinking water—among the most valuable resources on the planet—to transport human waste, Herrington says.

“It’s not yet a big deal in Canada because we have so much fresh water, but that doesn’t mean it will always be the case,” she says. “We know the glaciers are shrinking and there’s not as much water coming off the mountains as there used to be.”

Still, loving Mother Earth the right way is secondary when most people buy a compostable toilet system.

Some homeowners are more money minded than eco-conscious, and compostable toilets provide an economical alternative to a full-blown, costly home renovation to install your run-of-the-mill flush toilet.

“If you want to put in a toilet in your basement where you didn’t have one, you’d have to smash up the basement floor to tie into the sewer system,” Herrington says, adding that could cost thousands of dollars. “With a compostable toilet, all you need to do is run a vent pipe out through the roof.”

Compostable toilets aren’t cheap, however, at least compared to buying the usual porcelain throne from a hardware store. Sun-Mar — the leading manufacturer of compostable toilets — has a base electric model that costs about $1,700.

But once installed, maintenance is surprisingly easy — though not as carefree as a typical flush toilet, Herrington says.

To start, you need to add bulking material to the toilet’s main drum. It’s a mix of peat moss, hemp stalks and beneficial microbes. Then, turn the crank a couple of times, rotating the drum to mix it up — and you’re good to go.

“What you then have to do throughout the use of the toilet is to keep adding bulking material—about one scoop per person per day—or as we like to say ‘One scoop for every poop.’”

Herrington says many people assume compostable toilets are the same thing as humanure toilets. But the humanure version is much more basic, essentially doing your business in a bucket, topping it with sawdust and emptying the bucket into a compost bin outside. While they’re an affordable option for the cabin, city bylaws prevent Calgarians from using humanure within city limits, Herrington says.

“By comparison, you can put a compostable toilet in your house — with the only caveat being it can’t be your only toilet,” she says. “You need at least one toilet connected to a septic system, holding tank or the municipal sewer system.”

Of course, a compostable can still be the primary throne for your home, she adds.

And contrary to common misconceptions, compostable toilets are not malodorous.

“They have that stigma but until you have actually been around an operating toilet, you don’t realize just how well they work.”